1. Field of the Invention
The present invention relates to novel diamine compounds, particularly those which are useful as a monomer for producing high polymers, and a method of producing the diamine compounds. It also relates to novel polyamideimide resins produced from the diamine compounds.
2. Description of Related Arts
Polyimide resins and polyamide resins have been used widely in various fields such as films, coverings of electric wires, adhesives, paints, laminates and the like making a good use of its excellent characteristics, in particular heat resistance. On the other hand, development of polyamideimide resins, polyester imide resins, polyether imide resins and the like have been under way in order to broaden the applicability of the polyimide resins and polyamide resins while maintaining their advantages.
However, polyimide resins, polyamide resins, polyamideimide resins and the like which are now used widely have poor molding characteristics although they have sufficient heat resistance. In order to keep the balance between the advantage and disadvantage of the resins, it has been studied to compound the base resins, i.e., polyimide resins, polyamide resins, polyamideimide resins and the like, with other reactive resins such as epoxy resins. However, this approach has been unsuccessful. Major problems are that the resulting resins are insoluble or slightly soluble in solvents due to poor solubility of the base resins, and that the base resins do not mix uniformly with the reactive resins in a desired proportion, with the result that no desired characteristics can be obtained by blending.
On the other hand, diamine compounds have been used as raw materials for producing polyimide resins, polyamide resins, polyamideimide resins and the like in order to give heat resistance thereto and also as a curing agent for epoxy reins and as intermediates for producing dyestuffs and the like. When aromatic diamines such as 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenylmethane are used to produce polyimide resins, polyamide resins, polyamideimide resins and the like, the resins obtained have poor molding characteristics although they have sufficient heat resistance as described above.